The present invention relates to a molding box apparatus suitable for forming a vertical split type flaskless mold assembly having mold parts arranged in a side-by-side relation, each unit being provided at both of its sides with cavity surfaces so that the contacting cavity surfaces of adjacent mold parts define a cavity therebetween, the mold assembly being further provided at its upper portion with a tunnel or cave like runner through which a molten metal is poured into the cavities.
As exemplarily shown in FIG. 4, a typical conventional flaskless mold assembly has a plurality of mold parts 44, 44 arranged in a side-by-side relation, each unit being provided at both of its sides with halves 42, 43 of a cavity 41 so that a multiplicity of cavities 41 are formed by the successive mold parts 44. In the use of this mold assembly, the pouring of molten metal into the cavities 41, 41 are made separately and independently for each of the cavities 41. This work is considerably troublesome and deteriorates the efficiency of the work seriously. In order to obviate this problem, tunnel or cave like runners are formed in the upper parts of the successive mold parts in communication with adjacent ones. The runners are connected through respective cavities through wells. In the casting, the molten metal is poured into the cavities through the continuous runners and wells. This type of mold assembly is disclosed in the specification of U.S. Pat. No. 4,072,180. This mold assembly, however, is difficult to produce. Particularly, the formation of the runner requires a troublesome manual work.